The arch timer configuration for a CPU might get reset after suspending
said CPU.
In order to reliably use the event stream in the kernel (e.g. for delays),
we keep track of the state where we can safely consider the event stream as
properly configured. After writing to cntkctl, we issue an ISB to ensure
that subsequent delay loops can rely on the event stream being enabled.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Make COMMAND_LINE_SIZE a kernel config option to configure command
line size as required per target.
Change-Id: I1fe01812fd04940987230286381b9ed11d630f19
Signed-off-by: Nagireddy Annem <nannem@codeaurora.org>
[ Upstream commit 71f8af1110101facfad68989ff91f88f8e2c3e22 ]
Tomas Paukrt reports that his SAM9X60 based system (ARM926, ARMv5TJ)
fails to fix up alignment faults, eventually resulting in a kernel
oops.
The problem occurs when using CONFIG_CPU_USE_DOMAINS with commit
e6978e4bf1 ("ARM: save and reset the address limit when entering an
exception"). This is because the address limit is set back to
TASK_SIZE on exception entry, and, although it is restored on exception
exit, the domain register is not.
Hence, this sequence can occur:
interrupt
pt_regs->addr_limit = addr_limit // USER_DS
addr_limit = USER_DS
alignment exception
__probe_kernel_read()
old_fs = get_fs() // USER_DS
set_fs(KERNEL_DS)
addr_limit = KERNEL_DS
dacr.kernel = DOMAIN_MANAGER
interrupt
pt_regs->addr_limit = addr_limit // KERNEL_DS
addr_limit = USER_DS
alignment exception
__probe_kernel_read()
old_fs = get_fs() // USER_DS
set_fs(KERNEL_DS)
addr_limit = KERNEL_DS
dacr.kernel = DOMAIN_MANAGER
...
set_fs(old_fs)
addr_limit = USER_DS
dacr.kernel = DOMAIN_CLIENT
...
addr_limit = pt_regs->addr_limit // KERNEL_DS
interrupt returns
At this point, addr_limit is correctly restored to KERNEL_DS for
__probe_kernel_read() to continue execution, but dacr.kernel is not,
it has been reset by the set_fs(old_fs) to DOMAIN_CLIENT.
This would not have happened prior to the mentioned commit, because
addr_limit would remain KERNEL_DS, so get_fs() would have returned
KERNEL_DS, and so would correctly nest.
This commit fixes the problem by also saving the DACR on exception
entry if either CONFIG_CPU_SW_DOMAIN_PAN or CONFIG_CPU_USE_DOMAINS are
enabled, and resetting the DACR appropriately on exception entry to
match addr_limit and PAN settings.
Fixes: e6978e4bf1 ("ARM: save and reset the address limit when entering an exception")
Reported-by: Tomas Paukrt <tomas.paukrt@advantech.cz>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 747ffc2fcf969eff9309d7f2d1d61cb8b9e1bb40 ]
Consolidate the user access assembly code to asm/uaccess-asm.h. This
moves the csdb, check_uaccess, uaccess_mask_range_ptr, uaccess_enable,
uaccess_disable, uaccess_save, uaccess_restore macros, and creates two
new ones for exception entry and exit - uaccess_entry and uaccess_exit.
This makes the uaccess_save and uaccess_restore macros private to
asm/uaccess-asm.h.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c001899a5d6c2d7a0f3b75b2307ddef137fb46a6 ]
Use unified assembler syntax (UAL) in headers. Divided syntax is
considered deprecated. This will also allow to build the kernel
using LLVM's integrated assembler.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8101b5a1531f3390b3a69fa7934c70a8fd6566ad ]
Stephen reported the following build warning on a ARM multi_v7_defconfig
build with GCC 9.2.1:
kernel/futex.c: In function 'do_futex':
kernel/futex.c:1676:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized]
1676 | return oldval == cmparg;
| ~~~~~~~^~~~~~~~~
kernel/futex.c:1652:6: note: 'oldval' was declared here
1652 | int oldval, ret;
| ^~~~~~
introduced by commit a08971e9488d ("futex: arch_futex_atomic_op_inuser()
calling conventions change").
While that change should not make any difference it confuses GCC which
fails to work out that oldval is not referenced when the return value is
not zero.
GCC fails to properly analyze arch_futex_atomic_op_inuser(). It's not the
early return, the issue is with the assembly macros. GCC fails to detect
that those either set 'ret' to 0 and set oldval or set 'ret' to -EFAULT
which makes oldval uninteresting. The store to the callsite supplied oldval
pointer is conditional on ret == 0.
The straight forward way to solve this is to make the store unconditional.
Aside of addressing the build warning this makes sense anyway because it
removes the conditional from the fastpath. In the error case the stored
value is uninteresting and the extra store does not matter at all.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87pncao2ph.fsf@nanos.tec.linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 75fea300d73ae5b18957949a53ec770daaeb6fc2 ]
The GNU assembler has implemented the "unified syntax" parsing since
2005. This "unified" syntax is required when the kernel is built in
Thumb2 mode. However the "unified" syntax is a mixed bag of features,
including not requiring a `#' prefix with immediate operands. This leads
to situations where some code builds just fine in Thumb2 mode and fails
to build in ARM mode if that prefix is missing. This behavior
discrepancy makes build tests less valuable, forcing both ARM and Thumb2
builds for proper coverage.
Let's "fix" this issue by always using the "unified" syntax for both ARM
and Thumb2 mode. Given that the documented minimum binutils version that
properly builds the kernel is version 2.20 released in 2010, we can
assume that any toolchain capable of building the latest kernel is also
"unified syntax" capable.
Whith this, a bunch of macros used to mask some differences between both
syntaxes can be removed, with the side effect of making LTO easier.
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b6ae256afd32f96bec0117175b329d0dd617655e upstream.
On AArch64 you can do a sign-extended load to either a 32-bit or 64-bit
register, and we should only sign extend the register up to the width of
the register as specified in the operation (by using the 32-bit Wn or
64-bit Xn register specifier).
As it turns out, the architecture provides this decoding information in
the SF ("Sixty-Four" -- how cute...) bit.
Let's take advantage of this with the usual 32-bit/64-bit header file
dance and do the right thing on AArch64 hosts.
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191212195055.5541-1-christoffer.dall@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Usually modules are loaded into small area prior to the kernel
text because they are linked with the kernel using short calls.
Compile-time instrumentation like GCOV or KASAN bloats code a lot,
and as a result huge modules no longer fit into reserved area.
This patch adds option CONFIG_MODULES_USE_VMALLOC which lifts
limitation on amount of loaded modules. It links modules using
long-calls (option -mlong-calls) and loads them into vmalloc area.
In few places exported symbols are called from inline assembly.
This patch adds macro for such call sites: __asmbl and __asmbl_clobber.
Call turns into single 'bl' or sequence 'movw; movt; blx' depending on
context and state of config option.
Unfortunately this option isn't compatible with CONFIG_FUNCTION_TRACER.
Compiler emits short calls to profiling function despite of -mlong-calls.
This is a bug in GCC, but ftrace anyway needs an update to handle this.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Patch-mainline: linux-arm-kernel @ 18/11/2014, 20:21:46
Change-Id: Iea7990a033c060c26f5782125fb63d6f96a9d218
Signed-off-by: Shubham Aggarwal <shubagga@codeaurora.org>
[ Upstream commit ca70ea43f80c98582f5ffbbd1e6f4da2742da0c4 ]
MCPM does a soft reset of the CPUs and uses common cpu_resume() routine to
perform low-level platform initialization. This results in a try to install
HYP stubs for the second time for each CPU and results in false HYP/SVC
mode mismatch detection. The HYP stubs are already installed at the
beginning of the kernel initialization on the boot CPU (head.S) or in the
secondary_startup() for other CPUs. To fix this issue MCPM code should use
a cpu_resume() routine without HYP stubs installation.
This change fixes HYP/SVC mode mismatch on Samsung Exynos5422-based Odroid
XU3/XU4/HC1 boards.
Fixes: 3721924c81 ("ARM: 8081/1: MCPM: provide infrastructure to allow for MCPM loopback")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 344eb5539abf3e0b6ce22568c03e86450073e097 ]
getuser() and putuser() (and there underscored variants) use two
strb[t]/ldrb[t] instructions when they are asked to get/put 16-bits.
This means that the read/write is not atomic even when performed to a
16-bit-aligned address.
This leads to problems with vhost: vhost uses __getuser() to read the
vring's 16-bit avail.index field, and if it happens to observe a partial
update of the index, wrong descriptors will be used which will lead to a
breakdown of the virtio communication. A similar problem exists for
__putuser() which is used to write to the vring's used.index field.
The reason these functions use strb[t]/ldrb[t] is because strht/ldrht
instructions did not exist until ARMv6T2/ARMv7. So we should be easily
able to fix this on ARMv7. Also, since all ARMv6 processors also don't
actually use the unprivileged instructions anymore for uaccess (since
CONFIG_CPU_USE_DOMAINS is not used) we can easily fix them too.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Allow compilation when CONFIG_ARM_DMA_USE_IOMMU is not
selected by providing necessary stub functions.
Change-Id: Idbd30fb84bfea491a13a3cfac8917004a40e487b
Signed-off-by: lokesh kumar <lokekuma@codeaurora.org>
Add macro for sdm670 to get next high priority interrupt.
Change-Id: I0e4d50889f6cbfcbfefcae3f4efc47a180bedb24
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
Signed-off-by: Shadab Naseem <snaseem@codeaurora.org>
This represents a rollup of a series of reverts, simplified are
modifications to remove fiq_glue and fiq_debugger references in:
arch/arm/common/Kconfig
arch/arm/common/Makefile
drivers/staging/android/Kconfig
drivers/staging/android/Makefile
And deletion of:
arch/arm/common/fiq_glue.S
arch/arm/common/fiq_glue_setup.c
drivers/staging/android/fiq_debugger/
The reverts specific to android-4.14 are as follows:
Revert "ANDROID: fiq_debugger: Remove wakelock.h dependencies"
This reverts commit f9cbd12ed7.
Revert "ANDROID: fiq_debugger: Add fiq_debugger.disable option"
This reverts commit 76d292f95a.
Revert "ANDROID: fiq_debugger: Add option to apply uart overlay by
FIQ_DEBUGGER_UART_OVERLAY"
This reverts commit 0ff9e291c1.
Revert "ANDROID: fiq_debugger: Add fiq_watchdog_triggered api"
This reverts commit 9c027e6c23.
Revert "ANDROID: fiq_debugger: Call fiq_debugger_printf through a
function pointer from cpu specific code"
This reverts commit 9200a45dc9.
Revert "ANDROID: fiq_debugger: add ARM64 support"
This reverts commit c9d6bc7ab0.
Revert "ANDROID: fiq_debugger: split arm support into fiq_debugger_arm.c"
This reverts commit efffceb1e9.
Revert "ANDROID: fiq_debugger: use pt_regs for registers"
This reverts commit bf32f8accc.
Revert "ANDROID: fiq_debugger: allow compiling without CONFIG_FIQ_GLUE"
This reverts commit 16c3248941.
Revert "ANDROID: fiq_debugger: rename debug->fiq_debugger"
This reverts commit d241f1dfc9.
Revert "ANDROID: fiq_debugger: move into
drivers/staging/android/fiq_debugger/"
This reverts commit 0dc1cccb4f.
Revert "ANDROID: ARM: fiq_debugger: Update tty code for 3.9"
This reverts commit 4b55137d5e.
Revert "ANDROID: ARM: fiq_debugger: lock between tty and console writes"
This reverts commit a8be462329.
Revert "ANDROID: ARM: fiq_debugger: add process context reboot command"
This reverts commit cb5774b503.
Revert "ANDROID: ARM: fiq_debugger: fix multiple consoles and make it
a preferred console"
This reverts commit aecfa53f35.
Revert "ANDROID: ARM: fiq_debugger: add support for kgdb"
This reverts commit 992dbb2a9a.
Revert "ANDROID: ARM: fiq_debugger: add debug_putc"
This reverts commit 5d12c56f2a.
Revert "ANDROID: ARM: fiq_debugger: add support for reboot commands"
This reverts commit 14dbf8675b.
Revert "ANDROID: ARM: fiq_debugger: Add generic fiq serial debugger"
This reverts commit 05e1c7f617.
Revert "ANDROID: ARM: fiq_glue: Add custom fiq return handler api."
This reverts commit e329aaf322.
Revert "ANDROID: ARM: fiq_glue: Add fiq_glue"
This reverts commit 47fe2f8d76.
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 32402555
Bug: 36101220
Change-Id: I3f74b1ff5e4971d619bcb37a911fed68fbb538d5
Add missing read and write no_log macros for support in 32-bit
arm.
CRs-Fixed: 2478833
Change-Id: Ib265c53201fe56c532287b4c9456b2adcf81827b
Acked-by: Bhaumik Vasav Bhatt <bbhatt@qti.qualcomm.com>
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>
[ Upstream commit be167862ae7dd85c56d385209a4890678e1b0488 ]
Patch series "compiler: allow all arches to enable
CONFIG_OPTIMIZE_INLINING", v3.
This patch (of 11):
When function tracing for IPIs is enabled, we get a warning for an
overflow of the ipi_types array with the IPI_CPU_BACKTRACE type as
triggered by raise_nmi():
arch/arm/kernel/smp.c: In function 'raise_nmi':
arch/arm/kernel/smp.c:489:2: error: array subscript is above array bounds [-Werror=array-bounds]
trace_ipi_raise(target, ipi_types[ipinr]);
This is a correct warning as we actually overflow the array here.
This patch raise_nmi() to call __smp_cross_call() instead of
smp_cross_call(), to avoid calling into ftrace. For clarification, I'm
also adding a two new code comments describing how this one is special.
The warning appears to have shown up after commit e7273ff49a ("ARM:
8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI"), which changed the
number assignment from '15' to '8', but as far as I can tell has existed
since the IPI tracepoints were first introduced. If we decide to
backport this patch to stable kernels, we probably need to backport
e7273ff49a as well.
[yamada.masahiro@socionext.com: rebase on v5.1-rc1]
Link: http://lkml.kernel.org/r/20190423034959.13525-2-yamada.masahiro@socionext.com
Fixes: e7273ff49a ("ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI")
Fixes: 365ec7b173 ("ARM: add IPI tracepoints") # v3.17
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Borislav Petkov <bp@suse.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1f5b62f09f6b314c8d70b9de5182dae4de1f94da ]
The VDSO code uses the kernel helper that was originally designed
to abstract the access between 32 and 64bit systems. It worked so
far because this function is declared as 'inline'.
As we're about to revamp that part of the code, the VDSO would
break. Let's fix it by doing what should have been done from
the start, a proper system register access.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5388a5b82199facacd3d7ac0d05aca6e8f902fed ]
machine_crash_nonpanic_core() does this:
while (1)
cpu_relax();
because the kernel has crashed, and we have no known safe way to deal
with the CPU. So, we place the CPU into an infinite loop which we
expect it to never exit - at least not until the system as a whole is
reset by some method.
In the absence of erratum 754327, this code assembles to:
b .
In other words, an infinite loop. When erratum 754327 is enabled,
this becomes:
1: dmb
b 1b
It has been observed that on some systems (eg, OMAP4) where, if a
crash is triggered, the system tries to kexec into the panic kernel,
but fails after taking the secondary CPU down - placing it into one
of these loops. This causes the system to livelock, and the most
noticable effect is the system stops after issuing:
Loading crashdump kernel...
to the system console.
The tested as working solution I came up with was to add wfe() to
these infinite loops thusly:
while (1) {
cpu_relax();
wfe();
}
which, without 754327 builds to:
1: wfe
b 1b
or with 754327 is enabled:
1: dmb
wfe
b 1b
Adding "wfe" does two things depending on the environment we're running
under:
- where we're running on bare metal, and the processor implements
"wfe", it stops us spinning endlessly in a loop where we're never
going to do any useful work.
- if we're running in a VM, it allows the CPU to be given back to the
hypervisor and rescheduled for other purposes (maybe a different VM)
rather than wasting CPU cycles inside a crashed VM.
However, in light of erratum 794072, Will Deacon wanted to see 10 nops
as well - which is reasonable to cover the case where we have erratum
754327 enabled _and_ we have a processor that doesn't implement the
wfe hint.
So, we now end up with:
1: wfe
b 1b
when erratum 754327 is disabled, or:
1: dmb
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
wfe
b 1b
when erratum 754327 is enabled. We also get the dmb + 10 nop
sequence elsewhere in the kernel, in terminating loops.
This is reasonable - it means we get the workaround for erratum
794072 when erratum 754327 is enabled, but still relinquish the dead
processor - either by placing it in a lower power mode when wfe is
implemented as such or by returning it to the hypervisior, or in the
case where wfe is a no-op, we use the workaround specified in erratum
794072 to avoid the problem.
These as two entirely orthogonal problems - the 10 nops addresses
erratum 794072, and the wfe is an optimisation that makes the system
more efficient when crashed either in terms of power consumption or
by allowing the host/other VMs to make use of the CPU.
I don't see any reason not to use kexec() inside a VM - it has the
potential to provide automated recovery from a failure of the VMs
kernel with the opportunity for saving a crashdump of the failure.
A panic() with a reboot timeout won't do that, and reading the
libvirt documentation, setting on_reboot to "preserve" won't either
(the documentation states "The preserve action for an on_reboot event
is treated as a destroy".) Surely it has to be a good thing to
avoiding having CPUs spinning inside a VM that is doing no useful
work.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 72cd4064fccaae15ab84d40d4be23667402df4ed ]
ARMv8M introduces support for Security extension to M class, among
other things it affects exception handling, especially, encoding of
EXC_RETURN.
The new bits have been added:
Bit [6] Secure or Non-secure stack
Bit [5] Default callee register stacking
Bit [0] Exception Secure
which conflicts with hard-coded value of EXC_RETURN:
In fact, we only care of few bits:
Bit [3] Mode (0 - Handler, 1 - Thread)
Bit [2] Stack pointer selection (0 - Main, 1 - Process)
We can toggle only those bits and left other bits as they were on
exception entry.
It is basically, what patch does - saves EXC_RETURN when we do
transition form Thread to Handler mode (it is first svc), so later
saved value is used instead of EXC_RET_THREADMODE_PROCESSSTACK.
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1b5ba350784242eb1f899bcffd95d2c7cff61e84 ]
Arm TC2 fails cpu hotplug stress test.
This issue was tracked down to a missing copy of the new affinity
cpumask for the vexpress-spc interrupt into struct
irq_common_data.affinity when the interrupt is migrated in
migrate_one_irq().
Fix it by replacing the arm specific hotplug cpu migration with the
generic irq code.
This is the counterpart implementation to commit 217d453d47 ("arm64:
fix a migrating irq bug when hotplug cpu").
Tested with cpu hotplug stress test on Arm TC2 (multi_v7_defconfig plus
CONFIG_ARM_BIG_LITTLE_CPUFREQ=y and CONFIG_ARM_VEXPRESS_SPC_CPUFREQ=y).
The vexpress-spc interrupt (irq=22) on this board is affine to CPU0.
Its affinity cpumask now changes correctly e.g. from 0 to 1-4 when
CPU0 is hotplugged out.
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit 383fb3ee8024d596f488d2dbaf45e572897acbdb upstream.
In big.Little systems, some CPUs require the Spectre workarounds in
paths such as the context switch, but other CPUs do not. In order
to handle these differences, we need per-CPU vtables.
We are unable to use the kernel's per-CPU variables to support this
as per-CPU is not initialised at times when we need access to the
vtables, so we have to use an array indexed by logical CPU number.
We use an array-of-pointers to avoid having function pointers in
the kernel's read/write .data section.
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit e209950fdd065d2cc46e6338e47e52841b830cba upstream.
Allow the way we access members of the processor vtable to be changed
at compile time. We will need to move to per-CPU vtables to fix the
Spectre variant 2 issues on big.Little systems.
However, we have a couple of calls that do not need the vtable
treatment, and indeed cause a kernel warning due to the (later) use
of smp_processor_id(), so also introduce the PROC_TABLE macro for
these which always use CPU 0's function pointers.
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit 945aceb1db8885d3a35790cf2e810f681db52756 upstream.
Call the per-processor type check_bugs() method in the same way as we
do other per-processor functions - move the "processor." detail into
proc-fns.h.
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit 65987a8553061515b5851b472081aedb9837a391 upstream.
Split out the lookup of the processor type and associated error handling
from the rest of setup_processor() - we will need to use this in the
secondary CPU bringup path for big.Little Spectre variant 2 mitigation.
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit afaf6838f4bc896a711180b702b388b8cfa638fc upstream.
Introduce C and asm helpers to sanitize user address, taking the
address range they target into account.
Use asm helper for existing sanitization in __copy_from_user().
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit e3aa6243434fd9a82e84bb79ab1abd14f2d9a5a7 upstream.
When Spectre mitigation is required, __put_user() needs to include
check_uaccess. This is already the case for put_user(), so just make
__put_user() an alias of put_user().
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit 621afc677465db231662ed126ae1f355bf8eac47 upstream.
A mispredicted conditional call to set_fs could result in the wrong
addr_limit being forwarded under speculation to a subsequent access_ok
check, potentially forming part of a spectre-v1 attack using uaccess
routines.
This patch prevents this forwarding from taking place, but putting heavy
barriers in set_fs after writing the addr_limit.
Porting commit c2f0ad4fc089cff8 ("arm64: uaccess: Prevent speculative use
of the current addr_limit").
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit 3aa2df6ec2ca6bc143a65351cca4266d03a8bc41 upstream.
Use __copy_to_user() rather than __put_user_error() for individual
members when saving VFP state.
This has the benefit of disabling/enabling PAN once per copied struct
intead of once per write.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This reverts commit 040c05c6e4.
ASan can handle the new memory layout in Android P and later, which
means this change can be reverted in 4.14.
Bug: 67425063
Signed-off-by: Evgenii Stepanov <eugenis@google.com>
Change-Id: I128de2797bca0bc17fe991e1cb48788ecf5f25de
Commit a3c0f84765bb429ba0fd23de1c57b5e1591c9389 upstream.
Spectre variant 1 attacks are about this sequence of pseudo-code:
index = load(user-manipulated pointer);
access(base + index * stride);
In order for the cache side-channel to work, the access() must me made
to memory which userspace can detect whether cache lines have been
loaded. On 32-bit ARM, this must be either user accessible memory, or
a kernel mapping of that same user accessible memory.
The problem occurs when the load() speculatively loads privileged data,
and the subsequent access() is made to user accessible memory.
Any load() which makes use of a user-maniplated pointer is a potential
problem if the data it has loaded is used in a subsequent access. This
also applies for the access() if the data loaded by that access is used
by a subsequent access.
Harden the get_user() accessors against Spectre attacks by forcing out
of bounds addresses to a NULL pointer. This prevents get_user() being
used as the load() step above. As a side effect, put_user() will also
be affected even though it isn't implicated.
Also harden copy_from_user() by redoing the bounds check within the
arm_copy_from_user() code, and NULLing the pointer if out of bounds.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit b1cd0a14806321721aae45f5446ed83a3647c914 upstream.
Fixing __get_user() for spectre variant 1 is not sane: we would have to
add address space bounds checking in order to validate that the location
should be accessed, and then zero the address if found to be invalid.
Since __get_user() is supposed to avoid the bounds check, and this is
exactly what get_user() does, there's no point having two different
implementations that are doing the same thing. So, when the Spectre
workarounds are required, make __get_user() an alias of get_user().
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit d09fbb327d670737ab40fd8bbb0765ae06b8b739 upstream.
Borrow the x86 implementation of __inttype() to use in get_user() to
select an integer type suitable to temporarily hold the result value.
This is necessary to avoid propagating the volatile nature of the
result argument, which can cause the following warning:
lib/iov_iter.c:413:5: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var]
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 42019fc50dfadb219f9e6ddf4c354f3837057d80 upstream.
__get_user_error() is used as a fast accessor to make copying structure
members in the signal handling path as efficient as possible. However,
with software PAN and the recent Spectre variant 1, the efficiency is
reduced as these are no longer fast accessors.
In the case of software PAN, it has to switch the domain register around
each access, and with Spectre variant 1, it would have to repeat the
access_ok() check for each access.
Use __copy_from_user() rather than __get_user_err() for individual
members when restoring VFP state.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613 upstream.
Add an implementation of the array_index_mask_nospec() function for
mitigating Spectre variant 1 throughout the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a78d156587931a2c3b354534aa772febf6c9e855 upstream.
Add assembly and C macros for the new CSDB instruction.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit add5609877c6785cc002c6ed7e008b1d61064439 upstream.
Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected
CPUs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3c908e16396d130608e831b7fac4b167a2ede6ba upstream.
Include Brahma B15 in the Spectre v2 KVM workarounds.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 0c47ac8cd157727e7a532d665d6fb1b5fd333977 upstream.
In order to avoid aliasing attacks against the branch predictor
on Cortex-A15, let's invalidate the BTB on guest exit, which can
only be done by invalidating the icache (with ACTLR[0] being set).
We use the same hack as for A12/A17 to perform the vector decoding.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3f7e8e2e1ebda787f156ce46e3f0a9ce2833fa4f upstream.
In order to avoid aliasing attacks against the branch predictor,
let's invalidate the BTB on guest exit. This is made complicated
by the fact that we cannot take a branch before invalidating the
BTB.
We only apply this to A12 and A17, which are the only two ARM
cores on which this useful.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f5fe12b1eaee220ce62ff9afb8b90929c396595f upstream.
In order to prevent aliasing attacks on the branch predictor,
invalidate the BTB or instruction cache on CPUs that are known to be
affected when taking an abort on a address that is outside of a user
task limit:
Cortex A8, A9, A12, A17, A73, A75: flush BTB.
Cortex A15, Brahma B15: invalidate icache.
If the IBE bit is not set, then there is little point to enabling the
workaround.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 9d3a04925deeabb97c8e26d940b501a2873e8af3 upstream.
Add support for per-processor bug checking - each processor function
descriptor gains a function pointer for this check, which must not be
an __init function. If non-NULL, this will be called whenever a CPU
enters the kernel via which ever path (boot CPU, secondary CPU startup,
CPU resuming, etc.)
This allows processor specific bug checks to validate that workaround
bits are properly enabled by firmware via all entry paths to the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 26602161b5ba795928a5a719fe1d5d9f2ab5c3ef upstream.
Check for CPU bugs when secondary processors are being brought online,
and also when CPUs are resuming from a low power mode. This gives an
opportunity to check that processor specific bug workarounds are
correctly enabled for all paths that a CPU re-enters the kernel.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a5b9177f69329314721aa7022b7e69dab23fa1f0 upstream.
Prepare the processor bug infrastructure so that it can be expanded to
check for per-processor bugs.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit f5683e76f35b4ec5891031b6a29036efe0a1ff84 upstream.
Add CPU part numbers for Cortex A53, A57, A72, A73, A75 and the
Broadcom Brahma B15 CPU.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5d81f7dc9bca4f4963092433e27b508cbe524a32 upstream.
Now that all our infrastructure is in place, let's expose the
availability of ARCH_WORKAROUND_2 to guests. We take this opportunity
to tidy up a couple of SMCCC constants.
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 55e3748e8902ff641e334226bdcb432f9a5d78d3 upstream.
In order to offer ARCH_WORKAROUND_2 support to guests, we need
a bit of infrastructure.
Let's add a flag indicating whether or not the guest uses
SSBD mitigation. Depending on the state of this flag, allow
KVM to disable ARCH_WORKAROUND_2 before entering the guest,
and enable it when exiting it.
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 44a497abd621a71c645f06d3d545ae2f46448830 upstream.
kvm_vgic_global_state is part of the read-only section, and is
usually accessed using a PC-relative address generation (adrp + add).
It is thus useless to use kern_hyp_va() on it, and actively problematic
if kern_hyp_va() becomes non-idempotent. On the other hand, there is
no way that the compiler is going to guarantee that such access is
always PC relative.
So let's bite the bullet and provide our own accessor.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Julien Thierry